A good starting point is asking friends and family for jewelry store recommendations. Look for membership in the American Gem Society. Also, check them out with the Better Business Bureau and search for online complaints.

5 In-Store Tips
We’ll get into more detail about what to look for when you’re buying a diamond, another gemstone or gold. But here are some jeweler tricks of the trade to be aware of when you walk in the store:

Inflated discounts. If the clerk is saying the ring has been discounted by 50 percent or more, be wary. The profit margin in jewelry is not high enough to make a discount like that probable. Also be on guard for a high appraisal and a low selling price.

Hidden flaws. The setting of a ring can be used to hide flaws in a diamond or other gemstone. When you’re buying a diamond, you’ll want to examine it with a jeweler’s loupe. Ask the jeweler to show you how to use it properly.

Tricky lighting. Make sure you examine the diamond or other gem in different types of lighting, including natural lighting. The store’s lighting might make cloudiness or other imperfections difficult to see.

Enhancements. Has the stone been treated to remove or hide imperfections? You’ll want to ask. Consumer Reports says:

Sapphires and rubies are often subjected to high heat to improve their transparency and color. And there are a number of techniques to improve the clarity of diamonds, including laser drilling, which can vaporize tiny carbon specks. The holes are so small they’re very difficult to see. But if you look at the side of the stone in very bright light it might show some thin “threads.” Sometimes a chemical is used to fill small cracks in a diamond to make it appear more brilliant.

Pressure sales tactics. Beware of jewelers who pressure you to make a purchase. Instead, take the time to compare jewelry at several stores.

Now, let’s look at what you’ll need to know after you’ve decided what type of jewelry you’ll be purchasing and before you head to the store. You’ve got to study up to be sure you’re getting a quality product at a fair price. Both the American Gem Society and the Jewelry Information Center, which is run by the Jewelers of America, have extensive guides to buying diamonds, gold and other high-end jewelry.

Focus on the four C’s – color, cut, clarity and carats. These determine the value of a diamond.

Colorless diamonds are the most valuable, and the most rare. The Gemological Institute of America developed a color scale, ranging from D (meaning the diamond is colorless) to Z. Those further down in the alphabet are more yellow. To see a diamond’s true color, don’t look at it against a black background. Instead, look at it against white, so you can see how the diamond contrasts with the white background.

Each stone should be cut using a precise mathematical formula, which is designed to bring out its brilliance and fire. If the cut is too deep or too shallow, the diamond will lose some luster.

Clarity describes a diamond’s imperfections and irregularities, and is graded from flawless to imperfect. Examine the diamond with a loupe to look for flaws.

Carats indicate the weight of a diamond, and 142 carats equals 1 ounce. Larger diamonds are rarer, making them typically worth more per carat.

Other Gemstones
Jewelry with colored gemstones, such as rubies, sapphires and emeralds, also are popular gifts. Keep these things in mind:

Natural gemstones have been mined, and some may be enhanced to improve their color and durability. But the treatment may reduce the gem’s value. The effects of some treatments also may wear off over time, or mean your piece requires special care, according to the American Gem Society.

The seller should disclose whether the gemstone has been enhanced, and if any special care is required.

You also may encounter synthetic stones, which have been created in the laboratory. They’re identical to natural gemstones, but because they haven’t been mined they aren’t as rare or as costly.

There also are imitation stones, which resemble gems, but could actually be glass, plastic or an inexpensive stone.

A karat mark disclosing the percentage of pure gold in the piece is very common, although it’s not required. Consumer Reports says:

But any piece of jewelry that displays a karat mark must also be stamped with the manufacturer’s trademark. A piece that has a karat mark but no manufacturer’s trademark should always raise a red flag.

While pure gold is 24K, it’s very soft and easy to damage, so gold is usually alloyed with other metals, such as silver and copper, to make it more durable. An 18K gold piece is 75 percent pure gold.

The higher the karats, the more expensive the piece will be.

Jewelry must be at least 10K to be sold as gold in the U.S.

Keep Your Records
To protect yourself, make sure you get all the details of your purchase in writing. Your sales receipt or an appraisal is considered a contract and can be used to prove what the jeweler told you.

With diamonds or gemstones, request a grading report from an independent gemological lab, and be sure to keep it with your new treasure.

Karen Datko contributed to this post.

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.